TikZ 节点标签对齐

Question

我今天开始学习 TikZ，并得到了以下图像：

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{graphs,positioning,arrows,shapes.misc,decorations.pathmorphing}

\tikzset{
    >=stealth,
    every picture/.style={thick},
    graphs/every graph/.style={empty nodes},
}

\tikzstyle{vertex}=[
    draw,
    circle,
    fill=black,
    inner sep=1pt,
    minimum width=5pt,
]

\begin{document}
\begin{tikzpicture}
    \begin{scope}
        \graph[ grow right = 2 ] {
            u [vertex, label=$u$]
            --[edge label=$e$]
            v [vertex, label=$v$]
        };
    \end{scope}
    \draw[->,thin] (3,0) -- (5,0) node [midway,above] {subdividing};
    \begin{scope} [xshift=6cm]
        \graph[ grow right = 1 ] {
            u  [vertex, label=$u$]
            -- %[edge label=$e_{uv}$]
            e  [vertex, label=$v_e$]
            -- %[edge label=$e_{vu}$]
            v  [vertex, label=$v$]
        };
    \end{scope}
\end{tikzpicture}
\end{document}

有没有办法自动将v_e标签与右侧图表中u的垂直对齐？v

另外，我喜欢这种graph语法，但我还没有找到一种简单的方法让它在圆圈旁边制作节点标签（如图所示），而不是在圆圈内制作名称节点，而无需明确使用该label选项。

Answer 1

我不确定这里是否有必要。如果设置为，则s\smash不需要它。但是，它似乎是 所必需的。但这可能是由于我不熟悉该库。edge labelanchormidnode labelgraphs

您可以使用该quotes库来更轻松地标记edges，但我认为您仍然需要label标记nodes。

\documentclass[border=20pt,tikz]{standalone}
\usetikzlibrary{graphs,quotes,positioning}

\tikzset{
  >=stealth,
  every picture/.style={thick},
  graphs/every graph/.style={empty nodes},
  every edge quotes/.append style={above=7.5pt, anchor=mid, inner sep=0pt},
  every label/.append style={above=2.5pt, anchor=mid, inner sep=0pt},
  vertex/.style={
    draw,
    circle,
    fill=black,
    inner sep=0pt,% doesn't actually change the size and makes it easier to calculate things - or, more accurately, it makes it more obvious how to calculate them
    outer sep=0pt,
    minimum size=5pt,
  },
}

\begin{document}
\begin{tikzpicture}
  \graph[ grow right = 2 ] {
    u [vertex, label=$u$]
    -- ["$e$"]
    v [vertex, label=$v$]
  };
  \draw (3,0) edge ["subdividing",->,thin] (5,0);
  \begin{scope} [xshift=6cm]
    \graph[ grow right = 1 ] {
      u  [vertex, label=$u$]
      -- ["$e_{uv}$"]
      e  [vertex, label=$v\smash{_e}$]
      -- ["$e_{vu}$"]
      v  [vertex, label=$v$]
    };
  \end{scope}
\end{tikzpicture}
\end{document}

\smash请注意，中的下标似乎没有必要使用$e_{uv}$。